Tape guide arrangement for a transversely scanning magnetic recorder

Abstract

A transversely scanning magnetic tape recorder having a concave tape guide member which shapes and aligns the tape at a location by the rotating magnetic heads and between two cylindrical tape guides. The magnetic tape is deformed in cross-section from straight to curved and then back from curved to straight. To prevent kinks and folds in the magnetic tape as a result of this deformation, tape curving means exert pressure on the magnetic tape to increase the local degree of curvature of the magnetic tape. As a result, differences in local membrane stress in the tape cross-section at the location of the rotary magnetic head paths are reduced.

What is claimed is: 
     
       1. A tape guide arrangement for a transversely scanning magnetic tape recorder comprising: rotary magnetic head means for scanning a coated side of a tape in the recorder, including at least one head rotated about an axis parallel to a longitudinal direction of tape travel,   concavely curved tape guide means for guiding the tape in a locally transversely curved shape past the head means, said guide means having one concave guide portion disposed upstream from the head means and another concave guide portion disposed downstream from the head means,   at least first and second cylindrical tape guides for guiding the tape in a transversely straight shape, said first cylindrical guide being disposed upstream and spaced a given distance from said one guide portion, said second cylindrical guide being disposed downstream from the other guide portion, the shape of the magnetic tape cross-section during its movement from said upstream cylindrical guide to said downstream cylindrical guide changing from straight to curved and subsequently again from curved to straight, and   additional means for curving the tape disposed between said first cylindrical guide and said one guide portion, said additional means including at least one member which exerts a local pressure on the tape at equal distances inward from the edge of the magnetic tape to locally increase the degree of curvature of the tape so as to reduce differences in local membrane stress in the cross-section of the magnetic tape at the location of the scanning paths of the magnetic head means.   
     
     
       2. A guide arrangement as claimed in claim 1, including a second additional means for curving the tape disposed between said another concave guide portion and the second cylindrical guide. 
     
     
       3. A guide arrangement as claimed in claim 1 wherein said member is a rounded pressure member arranged to exert local pressure on the coated side of the magnetic tape at a location nearer said first cylindrical tape guide than said nearer guide portion. 
     
     
       4. A guide arrangement as claimed in claim 3 wherein said member is a curved body of revolution mounted for rotation about an axis transverse to said direction of tape movement. 
     
     
       5. A guide arrangement as claimed in claim 4 wherein the means for curving includes two such members, symmetrically curved and arranged symmetrically with respect to the edges of the tape. 
     
     
       6. A guide arrangement as claimed in claim 4 wherein said element is a sphere. 
     
     
       7. A guide arrangement as claimed in claim 1 wherein said additional means for curving comprises two pressure members arranged to contact the side of the tape opposite said coated side at symmetrically arranged locations near the edge of the magnetic tape, at a location closer to the concave guide member than to the first cylindrical tape guide. 
     
     
       8. A guide arrangement as claimed in claim 7 wherein said guide members are cylindrical rollers each mounted for rotation about an axis transverse to said direction of tape movement.